According to the invention, there is provided a novel soybean variety designated XB26U05. This invention thus relates to the seeds of soybean variety XB26U05, to the plants of soybean XB26U05 to plant parts of soybean variety XB26U05 and to methods for producing a soybean plant produced by crossing plants of the soybean variety XB26U05 with another soybean plant, using XB26U05 as either the male or the female parent.